VICTORIA – The B.C. legislature’s signature copper-clad dome is “beginning to twist, and that’s a problem,” MLAs on the legislature management committee were told Thursday.

That’s the most dramatic symptom of deterioration in the 120-year-old structure, whose many structural problems have been put off for decades and could cost up to $70 million to repair.

Legislature clerk Craig James reviewed highlights of an updated engineering report that shows the delicacy of the task.

“The problem with every part of this building is that when you go to fix one part of it, it’s attached to another part, which requires to be fixed as well,” James said. “In fixing, for instance, the dome, it sits on these columns that are supported centrally throughout the rotunda, and we’re advised that if you fix the dome, you should really be looking at and fixing the central portion too.”

The MLA committee is to meet again Dec. 12 to hear from engineers and decide on the next steps. Speaker Linda Reid noted that other legislature renovations have involved moving government operations to another location for as long as 10 years.

The estimate for the most urgent work is $5.7 million, proposed to begin in 2015.

Construction on the limestone structure started in 1893, with additions complete in 1915. It has many plumbing and electrical problems, and does not meet current fire or building codes.

Other buildings on the grounds also have serious problems, including the former armoury behind the legislature whose upper floor has been declared unsafe for use.